Slow vehicles, such as a ship, are typically easy to detect due to their large signature, slow speed and limited maneuverability—all are causes making them easy to hunt, for example, from the air. Ships are also limited in their Line Of Sight (LOS) dependent warning means, such as RADAR or Electronic Intelligence (Elint) Measures to the horizon range (typically few tens of kilometers). Thus, an early alert is hard to achieve. It is therefore desirable to enhance the capabilities of a ship to avoid being located by a remote sensor, and to extend the range of early alert by extending the range of its detection means. This remote sensor may typically be associated with emission of electromagnetic radiation, e.g., from the sensor itself or from the vehicle on which it is mounted, and therefore may be regarded as an emitter.
Typically a ship would have a set of receivers whose antennas would be mounted as close as possible to the tip of its mast (so as to extend the line of sight). These receivers would be searching the frequency ranges of radiation from the known emitters and gauge their directions and ranges. Typically, in hostile situations a ship would be reluctant to activate its radar and thus announce its presence. As soon as an emitter is detected, the ship would activate countermeasure, such as shooting a chaff rocket to explode a certain distance between the emitter and the ship. The chaff would bloom and stay for a period of time and would act as a decoy, luring the emitter away from the ship, which could then maneuver away under some screening countermeasures. Alternatively, the ship could similarly shoot an active decoy rocket. At the same time the ship could also employ its on-board active countermeasures to transmit signals to confuse or jam the sensor.
The actual parameters of these countermeasures are very complex and may depend on the ship movements, the wind conditions, the sensor technology, the sensor location and direction and many other parameters. A wrong decision may not only decrease the effectiveness of the protection but actually assist the hostile sensor in homing onto the ship. Decisions regarding the activation of countermeasures must be taken, implemented and deployed in the very short time between the alarm being given and the actual hit.
Limitations for extending the period of time available for the management of countermeasures include the short range of the horizon (LOS), the difficulty in quick assessment of the actual location of the emitter and the very short time for proper deployment of the countermeasures. It is therefore advantageous to provide system and method for extending the actual LOS of the countermeasure systems of a ship and to improve the ability of a ship to identify the location of an emitter while remaining at a safe distance.